Coal waste treatment processes and products, and their uses

ABSTRACT

Techniques for disposing of one or more toxic materials, such as coal waste (e.g., fly ash, sludge, etc.), include incorporating the toxic materials into artificial feldspar or forming artificial feldspar from the toxic material(s). The artificial feldspar may be used to form an artificial aggregate, which may be used in a construction material, as road base, as a fill material or for any other suitable purpose. Artificial aggregates that are formed from toxic materials are also disclosed, as are construction materials that include such artificial aggregates.

CROSS-REFERENCE TO RELATED APPLICATIONS

A claim for the benefit of priority to the Apr. 26, 2013 filing date of U.S. Provisional Patent Application No. 61/816,160, titled COAL WASTE TREATMENT PROCESSES AND PRODUCTS, AND THEIR USES (“the '160 Provisional Application”), is hereby made pursuant to 35 U.S.C. §119(e). In addition, this application is a continuation-in-part of U.S. application Ser. No. 13/646,365, filed on Oct. 5, 2012 and titled NANO FLEX HLW/SPENT FUEL RODS RECYCLING AND PERMANENT DISPOSAL (“the '365 Application”), in which a claim to the benefit of the Feb. 1, 2012 filing date of U.S. Provisional Patent Application No. 61/632,865, titled NANO FLEX HLW/SPENT FUEL RODS RECYCLING AND PERMANENT DISPOSAL (“the '865 Provisional Application”) is made under 35 U.S.C. §119(e). The entire disclosures of the '865 Provisional Application, the '365 Application and the '160 Provisional Application are hereby incorporated herein.

TECHNICAL FIELD

This disclosure relates to techniques for disposing of toxic materials, such as various byproducts of coal burning processes, including fly ash and toxic materials. More specifically, this disclosure relates to techniques and apparatuses for improving safety in handling and processing toxic materials for recycling and disposal, including incorporation of toxic materials into feldspar materials in amounts that match or are less than comparable materials naturally present at a selected disposal site.

BACKGROUND

The disclosed processes resolve issues that relate to the disposal of fly ash, other byproducts of coal power generation and other toxic and/or hazardous materials. In various embodiments, fly ash or other waste is incorporated into an artificial feldspar material, which is also referred to herein as “artificial feldspar.” The artificial feldspar is then disposed of or used for a variety of different purposes. Examples of other uses for the artificial feldspar include, but are not limited to, use as an aggregate (e.g., in concrete, in asphalt, etc.), as road base, as gravel, as another fill material or the like.

As illustrated by the pie chart of FIG. 1, in 2009, forty-four and nine tenths percent (44.9%) of all electricity generated in the United States came from coal power plants. Twenty-three and four tenths percent (23.4%) of electricity in the U.S. during that same year was generated by natural gas fired power plants. Nuclear power plants generated twenty and three tenths percent (20.3%) of electricity in the U.S. in 2009. Other sources of electricity in the U.S. in 2009 and their contributions to the overall U.S. power demand during that year are also shown in FIG. 1.

In recent years in the U.S., coal has been burned at a rate of 1.05 billion tons annually to generate electricity. In addition to generating electricity, a number of byproducts, or waste materials, are formed as coal is burned. These include fly ash, or furnace ash, of which about 72 million tons are generated each year in the U.S., cinder and sludge, as well as carbon dioxide, of which about 1.9 billion tons is produced in the U.S. each year, air pollutants and oxides of silicon, aluminum, iron, calcium, magnesium, titanium, sodium, potassium, arsenic, mercury, sulfur, uranium and thorium.

In addition, coal burning often releases radioactive materials, such as uranium-235, uranium-238 and thorium, and isotopes formed by the decay of radioactive materials, which are also known as “daughters.” These daughters may include materials such as radium, radon, polonium, bismuth, lead and potassium-40, all of which are hazardous materials. Any uranium-238 released as coal is burned may react with neutrons in the air (e.g., from oxygen bombardment, nitrogen nuclei generated by cosmic rays, etc.) to form plutonium-239. Other materials that are present in the waste that is generated by burning coal include mercury (at a current rate of about 109 tons per year), arsenic (at a current rate of about 7,884 tons per year), beryllium (at a current rate of about 1,167 tons per year), cadmium (at a current rate of about 750 tons per year), chromium (at a current rate of about 8,810 tons per year), nickel (at a current rate of about 9,339 tons per year), selenium (at a current rate of about 2,587 tons per year), uranium (at a current rate of about 801 tons per year; of which about 11,400 pounds are uranium-235) and thorium (at a current rate of about 1,971 tons per year). Altogether, toxic materials currently account for an estimated 120 million tons of the waste generated each year by coal burning power plants in the U.S. With about five hundred coal burning power plants currently in the U.S., this averages out to about 240,000 tons of toxic waste per power plant.

Before burning, coal is crushed and washed. The waste from these processes includes mercury, arsenic, beryllium, cadmium, nickel, selenium and acid mine runoff.

When the coal is burned, fly ash and sludge are formed. These byproducts also include mercury, arsenic, beryllium, cadmium, nickel and selenium, along with chromium, titanium, uranium and thorium, as well as toxic gases and a variety of radioactive materials. Although the gaseous waste that is generated when coal is burned is scrubbed to remove toxic components and prevent their release into the atmosphere, scrubbing processes also form toxic materials. As an example, scrubbing of coal with sulfur dioxide creates calcium sulfite (CaSO₃) and calcium sulfate (CaSO₄), both of which are toxic materials. The National Council on Radiation Protection and Measurements (NCRP) has determined that one ton of coal has a radiation of 0.00427 millicuries. At current rates, coal burning in the U.S. releases 4,483,500 millicuries of radiation into the environment each year. Based on current projections, by the year 2040, 11.716 billion tons of coal will be burned each year, resulting in an annual release of 145,230 tons of uranium (of which 5,883 tons will be uranium-235) and 1,039,709 tons of thorium into the environment.

At current energy production rates, it has been estimated that about seventy-two million (72,000,000) tons of fly ash is produced by coal burning power plants in the U.S. each year. Fly ash is typically stored in pits and landfills. The U.S. currently includes three hundred fifty (350) sites that have been approved and designated for permanent disposal of coal waste, including fly ash. Since all coal wastes are deposited in chemically active state, they release toxins over time. As rainwater filters through fly ash, toxic metals are leached from the fly ash into the water, which flows into the ground and ultimately contaminates groundwater and the biosphere. According to U.S. Environmental Protection Agency (EPA), a ten (10) acre fly ash landfill may introduce about 0.2 gallon to about ten (10) gallons of toxic metals into groundwater each day.

As demonstrated by the following table, each of the forty-nine continental states of the U.S. has at least one site that has been approved and designated for disposal of coal waste:

Tons Rank of Tons of Tons of Rank (Toxic Toxic Waste in Waste in State (Waste) Tons of Waste Metals) Metals Ponds Landfills Texas 1 13,454,000 1 8,915 576,810 6,490,800 Pennsylvania 2 11,057,650 4 5,639 1,076,700 2,536,500 Kentucky 3 8,599,400 6 4,853 2,298,000 3,409,900 Indiana 4 8,528,650 3 5,958 2,273,450 2,820,400 Ohio 5 7,836,700 2 6,594 2,667,300 899,900 West Virginia 6 6,190,900 5 4,990 896,200 3,118,400 Florida 7 5,180,787 12 3,029 74,000 1,335,300 Illinois 8 4,411,100 9 3,264 747,800 8,000 North Carolina 9 4,008,200 10 3,243 1,344,200 607,200 New Mexico 10 3,799,300 30 870 517,100 89,300 Georgia 11 3,508,910 7 4,192 1,541,900 825,610 Tennessee 12 3,505,220 16 2,176 632,100 732,600 Alabama 13 3,200,700 11 3,175 1,810,400 903,500 North Dakota 14 3,001,100 8 3,419 334,800 1,736,400 New York 15 2,838,410 29 1,000 — 699,990 Arizona 16 2,775,030 19 1,795 387,900 1,148,730 Utah 17 2,366,700 17 2,027 131,000 1,475,200 Missouri 18 2,332,150 14 2,469 779,150 221,700 Virginia 19 2,329,200 18 1,877 448,200 943,000 Michigan 20 2,129,700 13 2,524 669,200 769,500 Wyoming 21 2,106,300 23 1,306 448,100 950,400 South Carolina 22 2,091,490 15 2,315 301,050 377,100 Maryland 23 1,932,740 20 1,594 28,100 420,300 Louisiana 24 1,629,300 31 838 191,300 691,100 Colorado 25 1,607,970 21 1,442 5,700 655,080 Minnesota 26 1,544,110 28 1,022 813,910 420,400 Wisconsin 27 1,480,900 22 1,406 11,000 267,700 Oklahoma 28 1,462,300 27 1,180 16,560 123,900 Washington 29 1,405,220 39 279 — 424,220 Kansas 30 1,386,400 25 1,253 194,300 539,200 Mississippi 31 1,308,100 26 1,196 99,100 707,000 Iowa 32 1,228,100 24 1,284 201,700 151,600 Montana 33 1,018,900 37 364 963,600 — Maine 34 892,110 46 20 — 858,700 Arkansas 35 784,567 32 784 59,700 284,640 Nevada 36 771,600 36 391 — 477,200 New Jersey 37 642,300 35 488 — — Nebraska 38 595,000 33 630 — 166,500 Massachusetts 39 384,890 34 581 — — Delaware 40 284,100 38 316 — 149,000 New Hampshire 41 177,650 40 210 — 2,600 Connecticut 42 172,730 41 160 — — Oregon 43 99,900 42 114 — 17,500 South Dakota 44 97,300 43 82 000,000 0,080,100 Hawaii 45 51,500 44 46 — — California 46 50,400 45 38 — — Idaho 47 26,800 — — 0 0

The implementation of so-called coal gasification—converting coal into gas before combustion reduces the volume of produced waste, still poses very serious contamination issues and environmental risks. The table that follows provides a projection of the amounts of coal waste that result from coal gasification processes:

Number of New Projected Tons State Plants of Coal Waste Rank Texas 7 3,653,412 1 South Dakota 2 952,630 2 Nevada 3 888,272 3 Montana 3 848,278 4 Florida 2 736,649 5 South Carolina 2 731,110 6 Michigan 5 686,879 7 Illinois 3 632,521 8 Missouri 4 515,709 9 Wisconsin 3 512,632 10 Georgia 2 507,952 11 Wyoming 4 449,022 12 Pennsylvania 5 430,275 13 Kentucky 3 410,548 14 New Mexico 1 366,937 15 Ohio 1 325,864 16 Arkansas 2 316,691 17 Oklahoma 2 316,691 17 Iowa 2 312,755 19 Utah 3 296,257 20 Louisiana 2 294,414 21 North Carolina 1 251,099 22 West Virginia 2 247,775 23 Nebraska 2 199,063 24 Virginia 1 173,472 25 Colorado 1 169,656 26 North Dakota 1 93,797 27 Arizona 1 90,483 28

In January 2009, Sue Sturgis of the Institute of Southern Studies compiled a list of the top one hundred (100) U.S. coal burning power plants, in terms of coal waste stored in surface impoundments:

2006 Surface Impoundment Rank Facility Corporate Owner City State Releases (lbs.) 1 Stanton Energy Center Orlando Utilities Orlando FL 8,423,056 Commission 2 Sherburne County Xcel Energy Becker MN 4,721,862 Generating Plant 3 Coal Creek Station Great River Energy Underwood ND 4,372,709 4 Scherer Steam Electric Georgia Power/ Juliette GA 4,114,502 Plant Southern Company 5 Detroit Edison DTE Energy Monroe MI 4,110,859 Monroe Power Plant 6 Gibson Generating Duke Energy Owensville IN 3,030,524 Station 7 Gorgas Steam Plant Alabama Power/ Parrish AL 2,888,290 Southern Company 8 Cholla Power Plant Arizona Public Joseph City AZ 2,863,427 Service Company 9 Wansley Steam Plant Georgia Power/ Roopville GA 2,673,672 Southern Company 10 Ghent Generating E.ON US Ghent KY 2,664,501 Station 11 J.M. Stuart Station Dayton Power & Manchester OH 2,456,637 Light, Duke, AEP 12 Harllee Branch Georgia Power/ Milledgeville GA 2,433,945 Generating Plant Southern Company 13 Barry Steam Plant Alabama Power/ Bucks AL 2,350,349 Southern Company 14 Gaston Steam Plant Alabama Power/ Wilsonville AL 2,306,006 Southern Company 15 Miller Steam Plant Alabama Power/ Quinton AL 2,160,349 Southern Company 16 La Cygne Generating Great Plains Energy Lacygne KS 2,127,000 Station 17 Gallatin Fossil Plant Tennessee Valley Gallatin TN 2,093,068 Authority 18 Boswell Energy Minnesota Power Cohasset MN 2,009,628 Center 19 Leland Olds Station Basin Electric Power Stanton ND 1,937,821 Cooperative 20 Widows Creek Fossil Tennessee Valley Stevenson AL 1,864,177 Plant Authority 21 Paradise Fossil Plant Tennessee Valley Drakesboro KY 1,765,148 Authority 22 Labadie Power Station AmerenUE Labadie MO 1,740,882 23 Kingston Fossil Plant Tennessee Valley Harriman TN 1,738,437 Authority 24 Cardinal Plant American Electric Brilliant OH 1,707,225 Power 25 Bowen Steam Plant Georgia Power/ Cartersville GA 1,684,118 Southern Company 26 Pearl Station Soyland Power Pearl IL 1,661,744 Cooperative 27 New Madrid Power Associated Electric Marston MO 1,514,440 Plant Cooperative 28 Kammer and Mitchell American Electric Moundsville WV 1,372,687 Plants Power 29 Kyger Creek Station Ohio Valley Electric Cheshire OH 1,356,475 Corp. 30 Greene County Steam Alabama Power/ Forkland AL 1,343,973 Plant Southern Company 31 Baldwin Energy Dynegy Baldwin IL 1,324,467 Station 32 Rush Island Power AmerenUE Festus MO 1,307,769 Station 33 Karn and Weadock Consumers Energy Essexville MI 1,171,382 Generating Plants 34 Cayuga Generating Duke Energy Cayuga IL 1,154,623 Station 35 Council Bluffs Energy MidAmerican Energy Council IA 1,092,320 Center Bluffs 36 Chesterfield Power Dominion Chester VA 1,088,260 Station 37 Milton R. Young Minnkota Power Center ND 1,036,290 Station Cooperative 38 Wabash River Duke Energy W. Terre IN 951,610 Generating Station Haute 39 A. B. Brown Vectren Mount IL 944,944 Generating Station Vernon 40 Big Sandy Plant American Electric Louisa KY 915,079 Power 41 Amos Plant American Electric Winfield WV 864,024 Power 42 Big Cajun II NRG Energy New Roads LA 860,640 43 Hammond Steam Georgia Power/ Rome GA 849,068 Generating Station Southern Company 44 Tanners Creek Plant American Electric Lawrenceburg IN 819,840 Power 45 Muskingum River American Electric Beverly OH 791,757 Plant Power 46 Mayo Generating Progress Energy Roxboro NC 786,128 Plant 47 Killen Generating Dayton Power & Manchester OH 715,435 Station Light, Duke Energy 48 Roxboro Steam Plant Progress Energy Semora NC 698,290 49 Trimble County E.ON US Bedford KY 637,434 Generating Station 50 E.W. Brown E.ON US Harrodsburg KY 637,230 Generating Station 51 George Neal Station MidAmerican Energy Sergeant IA 612,005 North Bluff 52 Clifty Creek Station Ohio Valley Electric Madison IN 590,808 Corp. 53 Welsh Power Plant American Electric Pittsburg TX 562,064 Power 54 Coleto Creek Power International Power Fannin TX 550,623 Station 55 L. V. Sutton Electric Progress Energy Wilmington NC 548,210 Plant 56 Laramie River Station Basin Electric Power Wheatland WY 541,970 Cooperative 57 Lansing Smith Gulf Power/ Southport FL 520,282 Generating Plant Southern Company 58 Naughton Power Plant PacifiCorp/ Kemmerer WY 517,966 MidAmerican Energy 59 Meramec Power Plant AmerenUE Saint Louis MO 481,318 60 Shawnee Fossil Plant Tennessee Valley West KY 467,616 Authority Paducah 61 Brayton Point Station Dominion Somerset MA 464,254 62 Duck Creek Station Ameren Canton IL 462,272 63 Twin Oaks Power OptimEnergy Bremond TX 449,002 Station 64 Conesville Power American Electric Conesville OH 447,846 Plant Power 65 G.G. Allen Steam Duke Energy Belmont NC 439,208 Plant 66 Montrose Station Great Plains Energy Clinton MO 422,100 67 Allen Fossil Plant Tennessee Valley Memphis TN 416,705 Authority 68 Cliffside Plant Duke Energy Mooresboro NC 413,459 69 Asheville Plant Progress Energy Arden NC 411,793 70 Meredosia Power Ameren Meredosia IL 398,106 Station 71 Louisa Generating MidAmerican Energy Muscatine IA 382,063 Station 72 Asbury Generating Empire District Asbury MO 381,186 Station Electric Co. 73 H. W. Pirkey Power American Electric Hallsville TX 380,111 Plant Power 74 Yates Steam Georgia Pacific/ Newnan GA 376,610 Generating Plant Southern Company 75 Joppa Steam Plant Ameren Joppa IL 366,675 76 Havana Power Station Ameren Havana IL 360,772 77 Apache Generating Arizona Electric Cochise AZ 360,465 Station Power Cooperative 78 Canadys Station SCE&G/SCANA Canadys SC 357,897 79 Lee Steam Plant Progress Energy Goldsboro NC 356,078 80 Kincaid Generating Dominion Kincaid IL 355,108 Plant 81 Cape Fear Steam Plant Progress Energy Moncure NC 334,076 82 Intermountain Power Intermountain Power Delta UT 333,589 Station Service Corp. 83 Frank Ratts Hoosier Energy Petersburg IN 330,014 Generating Station 84 McDonough/ Georgia Power/ Smyrna GA 318,051 Atkinson Steam Plant Southern Company 85 Petersburg Generating AES Petersburg IN 309,961 Station 86 Dolet Hills Power Cleco Mansfield LA 291,208 Station 87 Rockport Plant American Electric Rockport IN 281,995 Power 88 Buck Steam Station Duke Energy Spencer NC 279,190 89 Hugo Plant Western Farmers Hugo OK 275,203 Electric Cooperative 90 Wood River Station Dynegy Alton IL 267,066 91 Gallagher Generating Duke Electric New Albany IN 260,183 Station 92 Oklaunion Power American Electric Vernon TX 254,652 Station Power 93 Gadsden Steam Plant Alabama Power/ Gadsden AL 249,740 Southern Company 94 Iatan Generating Great Plains Energy Weston MO 240,245 Station 95 Sioux Power Plant AmerenUE West Alton MO 226,193 96 Flint Creek Power American Electric Gentry AR 221,456 Plant Power 97 Riverton Power Plant Empire District Riverton KS 212,688 Electric Company 98 Spurlock Power East Kentucky Power Maysville KY 196,954 Station Cooperative 99 Jeffrey Energy Center Westar Energy Saint Marys KS 190,417 100 W.S. Lee Steam Duke Energy Pelzer SC 190,030 Station Total 114,790,602

The EPA has found that, since 2004, ninety percent (90%) of coal burning power plants in the U.S. violate the Clean Water Act. Many violations are accidental, but they all pose significant health risks and risks to the environment, particularly since combustion reduces the volume of coal by eighty-five percent (85%), which results in a significant increase in the concentration of all of the byproducts of coal burning processes. Some of the hazards of coal waste were apparent after Oct. 11, 2000, when an estimated three hundred six million (306,000,000) gallons of coal mining sludge burst through the bottom of a Massey Energy coal slurry impoundment in Martin County, Kentucky, filling Wolf Creek and Coldwater Fork, two tributaries of the Tug River. That disaster killed all aquatic life in the affected tributaries, leaving sludge over five feet thick along parts of their banks and adjacent land and poisoning the water supply for about 27,000 people. The Martin County coal fly ash slurry spill was thirty (30) times as big as the Exxon Valdez oil spill. Other fly ash spills, including the Tennessee Valley Authority (TVA) Kingston Fossil Plant coal fly ash slurry spill on Dec. 22, 2008 have had similarly disastrous effects on the environment.

There are a number of additional sites where similar disasters could happen. The EPA has released a list of “high hazard” dumps for coal waste (including fly ash), which includes the forty-four (44) sites listed below:

Owner Site Facility Location E.ON-owned Kentucky Ghent Generating Ash Pond Basin 1 Ghent, KY Utilities Company Station E.ON-owned Kentucky Ghent Generating Ash Pond Basin 2 Ghent, KY Utilities Company Station E.ON-owned Louisville Cane Run Station Ash Pond Louisville, KY Gas & Electric Co PPL Montana LLC Colstrip Steam Plant Units 1 & 2 Stage Colstrip, MT Evaporation Ponds (STEP) Progress Energy Asheville Plant 1982 Pond Arden, NC Carolinas Inc Progress Energy Asheville Plant 1964 Pond Arden, NC Carolinas Inc Allegheny Energy Pleasants Power Station McElroy' s Run Embankment Willow Island, WV American Electric Big Sandy Plant Fly Ash Louisa, KY Power American Electric Cardinal Plant Fly Ash Reservoir 2 Brilliant, OH Power American Electric Gavin Plant Fly Ash Pond Cheshire, OH Power American Electric Gavin Plant Bottom Ash Pond Cheshire, OH Power American Electric Amos Plant Fly Ash Pond St. Albans, WV Power American Electric Mitchell Plant Fly Ash Pond Moundsville, Power WV American Electric Muskingum River Plant Unit 5 Bottom Ash Pond Waterford, OH Power (Lower Fly Ash Pond) American Electric Muskingum River Plant Upper Fly Ash Pond Waterford, OH Power American Electric Muskingum River Plant Middle Fly Ash Pond Waterford, OH Power American Electric Philip Sporn Power Fly Ash Pond New Haven, WV Power Plant American Electric Tanners Creek Plant Fly Ash Pond Lawrenceburg, Power IN Arizona Electric Power Apache Generating Ash Pond 4 Cochise, AZ Cooperative Station Arizona Electric Power Apache Generating Ash Pond 1 Cochise, AZ Cooperative Station Arizona Electric Power Apache Generating Ash Pond 3 Cochise, AZ Cooperative Station Arizona Electric Power Apache Generating Scrubber Pond 2 Cochise, AZ Cooperative Station Arizona Electric Power Apache Generating Scrubber Pond 1 Cochise, AZ Cooperative Station Arizona Electric Power Apache Generating Evaporation 1 Cochise, AZ Cooperative Station Arizona Electric Power Apache Generating Ash Pond 2 Cochise, AZ Cooperative Station Arizona Public Service Cholla Generating Bottom Ash Pond Joseph City, AZ Company Station Arizona Public Service Cholla Generating Fly Ash Pond Joseph City, AZ Company Station Duke Energy G.G. Allen Steam Plant Active Ash Pond Belmont, NC Duke Energy Belews Creek Steam Active Ash Pond Walnut Cove, Station NC Duke Energy Buck Steam Station New Primary Pond Spencer, NC Duke Energy Buck Steam Station Secondary Pond Spencer, NC Duke Energy Buck Steam Station Primary Pond Spencer, NC Duke Energy Dan River Steam Secondary Pond Eden, NC Station Duke Energy Dan River Steam Primary Pond Eden, NC Station Duke Energy Marshall Steam Station Active Ash Pond Terrell, NC Duke Energy Riverbend Steam Secondary Pond Mount Holly, Station NC Duke Energy Riverbend Steam Primary Pond Mount Holly, Station NC Dynegy Midwest Havana Power Station East Ash Pond Havana, IL Generation Dynegy Midwest Wood River Station East Ash Pond (2 cells) Alton, IL Generation FirstEnergy Bruce Mansfield Power Little Blue Run Dam Shippingport, PA Station Southern Company- Branch Generating Plant E Milledgeville, owned Georgia Power GA E.ON-owned Kentucky E.W. Brown Generating Auxiliary Pond Harrodsburg, KY Utilities Company Station E.ON-owned Kentucky E.W. Brown Generating Ash Pond Harrodsburg, KY Utilities Company Station E.ON-owned Kentucky Ghent Generating Gypsum Stacking Facility Ghent, KY Utilities Company Station

In the U.S., coal waste dumps contain billions of gallons of fly ash and other toxic coal waste. All of these sites are threats to water supplies, human health and the environment.

SUMMARY

This disclosure includes methods for processing toxic waste, including the byproducts of coal burning processes, or “coal waste” or “coal combustion residuals” (“CCRs”), which includes fly ash, sludge and a variety of toxic materials. A method for processing toxic materials, such as coal waste, includes forming artificial feldspar that includes one or more toxic materials (e.g., fly ash, etc.). The artificial feldspar is tailored for use as an aggregate in concrete and other cementitious materials, as road base and/or for compatibility with a host site.

In a specific embodiment, fly ash and, optionally, other coal waste and/or additives are mixed with an aqueous material (e.g., water; sludge, or liquid waste, produced by coal crushing, cleaning and/or burning processes; etc.) and retained, or allowed to set. As the mixture sets, alumina silicate clusters form. Once alumina silicate clusters have formed, the mixture is introduced into a continuous flow/batch reactor (“CFR”) of a known type. In some embodiments, the CFR may heat the mixture to a temperature of up to 1,400° F., or an even higher temperature. The temperature of the CFR and the duration of time for which the mixture is subjected processing by the CFR may correspond to an intended compound and product (e.g., aggregate, road base, fill material, etc.) in terms of particle size, shape, density and other characteristics. The product traps any toxic materials present in the fly ash in a manner and concentration similar to those in which the toxic materials were originally present in coal, which may result in a product that is only about as toxic as the coal from which it was derived and, in some embodiments, may be less toxic than the coal from which it was derived. Thus, the safety of the product will not be as questionable as the safety of fly ash, and the product can be safely used in a variety of different ways, introduced into virtually any environment or disposed of in a safe and effective manner.

Environmentally safe compounds and products that result from such processes are also disclosed. An environmentally safe compound includes artificial feldspar formed from coal waste, including fly ash. Individual pieces or particles of the compound may have a configuration suitable for introduction into a predetermined disposal site, for example, they may match the configurations and other characteristics of pieces or particles of materials that are already present at the disposal site, including, without limitation, naturally occurring materials at the disposal site. Various embodiments of such configurations include aggregates for use with binders (e.g., cementitious binders, asphalt, etc.), as road base or as a fill material (e.g., gravel, sand, dirt, etc.).

In some embodiments, an environmentally safe compound may be incorporated into a material (e.g., a construction material, etc.) that may be used to form a structure. Non-limiting examples of such materials include cementitious materials (e.g., concrete, mortar, etc.) and asphalts. Thus, the predetermined disposal site may be a structure formed from a material that includes the environmentally safe compound. Alternatively, an environmentally safe compound that has been formed from coal waste, including fly ash, may be disposed of as a road base, as a fill material or in any other suitable manner.

Other aspects, as well as features and advantages of various aspects, of the disclosed subject matter will become apparent to those of ordinary skill in the art through consideration of the ensuing description, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a pie chart showing different categories of sources of electricity available in the United States of America in 2009 and the percentage of total electricity provided by each category of sources; and

FIG. 2 is an image of artificial feldspar made in accordance with teachings of this disclosure.

DETAILED DESCRIPTION

In various embodiments, methods for converting toxic materials, such as coal waste (e.g., fly ash, sludge, etc.) include forming artificial feldspar from the toxic materials or incorporating the toxic materials into artificial feldspar.

Such a process includes forming a mixture, or slurry, that includes toxic material(s). In embodiments where the toxic material(s) comprise(s) coal waste, the mixture may include fly ash and an aqueous component (e.g., water, sludge, other liquid waste, etc.). Some mixtures may include one or more additives that will impart the resulting artificial feldspar with one or more desired characteristics. As a non-limiting example, in embodiments where the artificial feldspar comprises an aggregate, anorthite (e.g., in the form of crushed dolomite, etc.) may be added to the mixture in an amount sufficient to impart the artificial aggregate with a desired amount of durability (e.g., about eight percent (8%), by weight of the mixture, to about twelve percent (12%), by weight of the mixture, etc.). After forming the mixture, it is retained, or allowed to set. As the mixture sets, alumina silicate clusters form. The alumina silicate clusters contain the toxic materials.

After alumina silicate clusters have formed, the mixture is introduced into a continuous flow reactor (CFR) of a known type. The CFR may be part of a fixed facility or it may comprise a mobile unit. As another alternative, naturally occurring fumaroles may be used as a CFR to convert the toxic material(s) to (an) environmentally safe product(s).

The temperature to which the mixture is exposed in the CFR, and the amount of time that the mixture is exposed to the elevated temperature of the CFR are tailored to provide artificial feldspar with desired characteristics. In some embodiments, a CFR may heat the mixture to a temperature of up to 1,400° F.

In embodiments where the toxic material comprises coal waste, subjecting the mixture to CFR processing will heat mercury in the coal waste, and cause the mercury to evaporate. The evaporated mercury may be collected. In vapor form, the mercury can be collected by passing the entire gas stream released from the CFR through a series of centrifuges, which separate the mercury vapors on the basis of density. Alternatively, the mercury may be condensed, then collected and used (or sold) for a variety of purposes.

The artificial feldspar that results from such a process has at least two predetermined properties. The CFR process provides each artificially made feldspar molecule with an initial content of (4) molecules of water, leaving four (4) additional sites available for water molecules to occupy of the eight (8) total available sites on each feldspar molecule. Thus, the artificial feldspar will be unable to transport solutes until eight (8) water molecules have associated themselves with the feldspar molecule—an event that takes at least 10,000 years to occur in natural sites that are not normally exposed to liquid groundwater. In addition, the CFR process forms a silicon coating on the artificial feldspar, encasing any toxic materials present in the artificial feldspar.

The CFR is configured to provide an environmentally safe product with a desired physical configuration (e.g., particle size, shape, etc.). When a CFR is used to form artificial feldspar, it is possible to form the artificial feldspar into any of a variety of configurations, including small particles, pellets, larger pieces and molded block. The artificial feldspar may be configured in a manner suitable for its intended use. A few examples include dry masonry, artificial aggregates, road base and fill materials. FIG. 2 provides an image of a specific embodiment of artificial feldspar, or an environmentally safe product, that may be formed by such a process.

Processes for forming artificial feldspar may be performed without the production of any byproducts that require additional purification (i.e., unsafe byproducts, etc.).

Artificial aggregates may be configured for use in a variety of materials, including, without limitation, concrete and other cementitous materials, asphalt and other construction materials. An artificial aggregate may be tailored to have a desired hardness and/or durability. As an example, an artificial aggregate that includes dolomite or another source of anorthite may have a rating of nine (9) out of ten (10) on the Los Angeles Scale of Strength and Durability. Some embodiments of artificial aggregate may have a higher strength and durability than aggregate obtained from naturally occurring sources.

Construction materials that include artificial aggregate are useful for forming a variety of structures, including, but not limited to, pavement. Artificial aggregates may have a configuration (e.g., shape, dimensions, etc.) that matches or substantially matches the configuration of natural aggregates.

As a fill material, the artificial feldspar may comprise common engineering fill (e.g., 85% to 87% of MDD at OMC, reference ASTM or AASHTO, etc.). While fill materials that have been formed from artificial feldspar can be placed virtually anywhere, a few suitable locations include underground mines (e.g., mines that are subject to remediation and closure, etc.), open pit mines, berms, dikes and trenches. In some embodiments, artificial feldspar that is in the form of a fill material may be put into place in the same manner as ordinary engineering fill, then protected from surface water via a high plastic clay cap (common in civil engineering) having a thickness of about two fee to about three feet and covered with at least feet of crushed rejects from any asphalt, concrete or stone production quarry/facility (e.g., for protection against flash floods, etc.).

In embodiments where the toxic material comprises coal waste, the toxic waste may be converted to an environmentally safe product at or near the coal burning power plant. In other embodiments, the process of converting toxic waste into an environmentally safe product is performed at or near a site where the environmentally safe product is to be used or otherwise disposed of. Conversion of toxic waste to an environmentally safe product at such a location will minimize issues related to handling and transportation.

In addition to reducing the detrimental impact of coal waste on the environment by providing a safe use for coal waste and other toxic materials, the production of artificial feldspar will have an added positive impact on the environment by reducing the need for exploration for aggregates, road base and fill materials. In addition, the use of coal waste to product artificial feldspar may reduce or eliminate the costs associated with identifying new sources for aggregates, road base and fill materials.

Additional information that may be useful in conjunction with the various aspects of the disclosed subject matter is set forth in International patent application no. PCT/US13/24232, filed on Jan. 31, 2013 and titled “NANO FLEX HLW/SPENT FUEL RODS RECYCLING AND PERMANENT DISPOSAL,” the entire disclosure of which is, by this reference, incorporated herein.

The disclosed embodiments should not be deemed to limit the scope of any of the claims that follow. The scope of each claim should be limited merely by its plain language, and should be deemed to include the full complement of available equivalents. 

What is claimed:
 1. A method for processing coal waste, comprising: mixing coal waste, including fly ash, with water to form a slurry; allowing the slurry to set until alumina silicate clusters form; introducing the slurry into a continuous flow reactor to form an environmentally stable product.
 2. The method of claim 1, wherein introducing the slurry into the continuous flow reactor comprises forming an aggregate.
 3. The method of claim 2, further comprising: introducing the aggregate into a cementitous binder.
 4. The method of claim 3, wherein introducing the aggregate into the cementitious binder comprises introducing the aggregate into a cementitious binder that includes further aggregate.
 5. The method of claim 2, further comprising: mixing the aggregate with asphalt.
 6. The method of claim 1, wherein introducing the slurry into the continuous flow reactor comprises forming road base.
 7. The method of claim 1, wherein introducing the slurry into the continuous flow reactor comprises forming a fill material.
 8. An environmentally safe compound for permanent storage of coal waste, comprising: artificial feldspar formed from coal waste, including fly ash, and having a configuration configured for introduction into a predetermined disposal site.
 9. The environmentally safe compound of claim 8, wherein the artificial feldspar has a configuration configured for use as an aggregate in a cementitious material or in asphalt.
 10. The environmentally safe compound of claim 9, wherein the artificial feldspar includes anorthite.
 11. The environmentally safe compound of claim 8, wherein the artificial feldspar has a configuration configured for use as a fill material.
 12. The environmentally safe compound of claim 8, wherein the artificial feldspar has a configuration suitable for use as a road base.
 13. A cementitious material, comprising: a cementitious binder; and aggregate dispersed throughout the cementitious binder, the aggregate including artificial feldspar formed from coal waste, including fly ash.
 14. The cementitious material of claim 13, comprising concrete.
 15. A pavement material, comprising: a binder; and aggregate dispersed throughout the binder, the aggregate including artificial feldspar formed from coal waste, including fly ash.
 16. The pavement material of claim 15, wherein the binder comprises a cementitious binder.
 17. The pavement material of claim 16, wherein the binder comprises asphalt. 